Hydraulically-actuated Electronically-controlled Unit Injectors (HEUI) for diesel engine fuel systems use hydraulic energy of pressurized oil to cause injection of the fuel into the engine cylinder. However, both the start and end of the fuel injection is electronically controlled through a solenoid on the injector. When an injector solenoid is energized it causes the injector poppet valve to lift off its seat which enables high pressure oil to enter the fuel injector causing injection of diesel fuel into the engine cylinder. When the injector solenoid is de-energized the injector oil discharge port is closed. Injection of fuel stops when the electrical signal to the solenoid stops which causes the injector poppet valve to close and the injector oil discharge port to open. Thus, each time an injector of a HEUI system fires it receives electronic signals and discharges oil under high pressure.
Each injector in a HEUI fuel injection system requires a pair of electrical wires for energizing its poppet valve. The electrical wires are connected to the top portion of the injectors that is located under the valve cover. It is the practice to have a bundle of wires, supported by a plurality of individual wire clamps, that are spaced along the length of the valve cover from which a pair of wires branches off to each injector. The individual wire clamps must be secured to the engine block adjacent each injector. The high pressure oil is discharged near the top of the injectors under the valve cover. The discharged high pressure oil must be returned to the low pressure engine sump through a drain. Since the oil is under considerable pressure it is discharged in a pressurized stream that must be controlled by deflecting it downwardly to prevent carryover and excessive lubrication of the valves stems, springs and rocker arms. This oil then flows downwardly to the engine sump. It has been the practice in the past to provide an individual deflector for each of the injectors which must be individually mounted on each injector hold down clamp under the valve cover.
Thus supporting the under valve cover wire harness and providing deflectors for the discharge oil requires numerous parts which must be individually secured to the injector hold down clamp. Each individual component must be properly aligned to insure that it performs as is intended. As a result, these individual components, as well as the assembly time devoted to these components, contribute a sizeable portion to the assembly cost of the engine. Also, when maintaining the engine, each of these individual components must be removed and then properly aligned and reassembled. This contributes considerable to the cost of some repair jobs.
Reference is hereby made to U.S. Pat. No. 5,245,970 for a disclosure of a HEUI system which patent is hereby included by reference as a part of this disclosure.
For the foregoing reasons, there is a need for an improved and more economical ways of supporting the under valve cover wiring harness and for deflecting the discharge oil from the HEUI injectors.